HM Digital Portable pH/EC/TDS/Temp Monitor HM-200

HM Digital Hydromaster 500 - Continuous pH/TDS/EC/Temp meter(MissingPowerCord)

Digital TDS EC Water Tester 0-9990ppm LCD Meter PPM Temp Purity Pen

HM Digital HM-100 Continuous pH/EC/TDS/Temp Monitor

MOODEAL Digital pH Meter LCD Backlight, Portable, Measures pH Temp TDS EC

4-in-1 Digital Water Tester TDS EC & Temperature Meter Portable